Is it permissible to lie and invent excuses to avoid going out with friends after work, in order to be able to study for a private exam?

Lying is forbidden except out of a pressing necessity for which no other legitimate means exists to achieve the purpose, and it must be restricted to the narrowest limits.

However, if the purpose can be achieved through truthfulness or tawriyah (allusory speech), then lying is forbidden. Tawriyah means using a word that carries two meanings, where the speaker intends a correct meaning, while the listener understands another meaning.

Speech is a means to achieve objectives. Thus, if every commendable objective can be attained by both truthfulness and lying, then lying in such a case is unlawful. But if it can be attained by lying and not by truthfulness, then lying is permissible if achieving that objective is permissible, and it is obligatory if the objective is obligatory, such as protecting oneself or a trust from oppressors.

The cautious approach is to use tawriyah, which is to intend a correct meaning by one's expression that is not a lie from their perspective, even if it appears to be a lie based on the literal wording.